1. Field of the Invention
The present invention regards the preparation of plant cell cultures belonging to the Dendrobium Phalaenopsis, Ansellia, Polyrrhiza, Vanilla, Cattleya and Vanda genera and their use in cosmetic, nutritional and pharmaceutical fields.
2. Description of the Related Art
The plants of the Dendrobium and Phalaenopsis genera belong to the Orchidaceae family. The Orchidaceae family is the second largest in the plant world after the Compositeae family and comprises about 735 genera divided into 25000 species. The Orchids of the Dendrobium, Phalaenopsis, Ansellia, Polyrrhiza, Vanilla, Cattleya and Vanda genera are epiphyte plants, i.e. they live on trees and grow on ligneous substrates. The epiphyte orchids, widespread in the Tropics, live fixed to forest trees, have a stalk with isolated or reduced, scale-like leaves and often have long sloping aerial roots, enclosed in the velamen which constitutes a sleeve with absorbing function around the root and with green photosynthesizing apex.
Numerous rare, dying species belong to the Dendrobium, Phalaenopsis, Ansellia, Polyrrhiza, Vanilla, Cattleya and Vanda genera, and as such they are protected from indiscriminate collection.
Numerous bioactive compounds have been isolated and identified in many orchid species. Tan Keng Hong et al (Journal of Chemical Ecology, 2006, 32(11):2429-2441) describe the presence of numerous phenylpropanoids in the flowers of Bulbophyllum vinaceum, while Ali Mohammad Babar et al (Plant Growth Regulation, 2006, 49(2-3): 137-146) report an increase of the phenylpropanoid synthesis in seedlings of Phalaenopsis in response to radiation-induced stress. The biological activities of phenylpropanoids have been widely described in the literature. In particular, these compounds are involved in the protection of proteins, lipids and nucleic acids from damage caused by free radicals (Gebhardt R. et al, 1997, Toxicol. Appl. Pharm. 144:279-286; Perez Garcia F. et al, 2000, Free Radical Res., 33: 661-665); they inhibit the biosynthesis of cholesterol, contribute to the prevention of atherosclerosis and of vascular disorders (Brown J. E. Et al, 1998, Free Radical Res., 29:247-255; Kraft K., 1997, 4: 369-378; Pittlern M H et al, Perfusion, 11:338-340), have hepaprotective, choleretic and diuretic activities (Dogan S. et al, 2005, J. Agric. Food Chem., 53:776-785), antiviral activities against HIV (Mcdougall B. et al, 1998, Antimicrob. Agents Ch., 42: 140-146; Shanina J. et al, 2001, Tetrahedron Lett., 42:3383-3385), antibacterial and antifungal activities (Martinov et al, 1999, Acta Horticulturae, 501:111-114; Zhu X F, 2005, Fitoterapia; 76: 108-111), anti-inflammatory and cicatrizing activities (Korkina et al., 2007, Cellular and Molecular Biology 53(5): 78-83) and potential tumor protection activities (Kurata R. et al, 2007, J. Agric. Food Chem. 55(1):185-190).
Several works in the literature show that hydrosoluble polysaccharides extracted from orchid plants belonging to the Dendrobium genus exert considerable immunomodulating and antioxidant activities (Zha, Xue-Qiang et al, 2007, Pharmaceutical Biology 45(1): 71-76; Luo A. et al, 2009, Int. J. Biol. Macromol. 45(4):359-63; Fan Y. Et al, 2009, Int. J. Biol. Macromol. 45(2): 169-73).
The availability of these bioactive compounds for commercial use is nevertheless tied to several restrictions:
1—limited availability of the plant material, since orchids are slow-growth plants and comprise numerous rare and protected species;
2—the presence of the above-described bioactive activities in the plant tissues of the orchids is subject to wide fluctuations tied to geographical origin, seasonal variability and contaminations of the cultivations by parasites;
3—the content of these compounds in plants is always quite low.